Support a QtCreator Builder using qtc and qtc5.

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Qt5 uses %qmake5_install

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Define macros required by Builder: qtc[5]

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
spectacle: Use %{?_smp_mflags} instead of the jobs macro construction.